Provided by: disper_0.3.1-2_all 
NAME
disper - on-the-fly display switcher
SYNOPSIS
disper [options] (-l|-s|-c|-e|-p|-i)
DESCRIPTION
Disper re-routes your screen output to one or more connected displays. For example when
giving a presentation, all one wants is that the beamer, which has just been connected, is
able to show whatever you prepared.
There is the option to either clone all detected displays, or extend the desktop to them.
Resolutions are automatically detected by default. For cloning, the highest resolution
supported by all displays devices is chosen; for extending every display device gets its
preferred or highest supported resolution. For special setups requiring more detailed
control, one can still use the vendor-supplied display configuration utilities.
OPTIONS
--version
show program's version number and exit
-h, --help
show this help message and exit
-v, --verbose
show what's happening
-q, --quiet
be quiet and only show errors
-r RESOLUTION, --resolution=RESOLUTION
set resolution, e.g. "800x600", or "auto" to detect the display's preferred
resolution, "max" to use the maximum resolution advertised, or "off" to disable the
display entirely. For extend it is possible to enter a single resolution for all
displays or a commaseparated list of resolutions (one for each display). Beware
that many displays advertise resolutions they can not fully show, so "max" is not
advised.
-d DISPLAYS, --displays=DISPLAYS
comma-separated list of displays to operate on, or "auto" to detect; the first is
the primary display.
-t DIRECTION, --direction=DIRECTION
where to extend displays: "left", "right", "top", or "bottom"
--scaling=SCALING
flat-panel scaling mode: "default", "native", "scaled", "centered", or
"aspect-scaled"
--plugins=PLUGINS
comma-separated list of plugins to enable. Special names: "user" for all user
plugins in ~/.config/disper/hooks; "all" for all plugins found; "none" for no
plugins.
--cycle-stages=CYCLE_STAGES
colon-separated list command-line arguments to cycle through; "-S:-c:-s" by default
ACTIONS
Select exactly one of the following actions
-l, --list
list the attached displays
-s, --single
only enable the primary display
-S, --secondary
only enable the secondary display
-c, --clone
clone displays
-e, --extend
extend displays
-p, --export
export current settings to standard output
-i, --import
import current settings from standard input
-C, --cycle
cycle through the list of cycle stages
FILES
$XDG_CONFIG_HOME/disper/config or ~/.config/disper/config or ~/.disper/config
Default command-line options to include at each disper invocation. Multiple lines
are concatenated, and lines starting with # are ignored. A typical example might
include:
# enable all plugins in ~/.config/disper/hooks
--plugins=user
# cycle over clone and extend
--cycle-stages='-c : -e'
$XDG_CONFIG_HOME/disper/hooks/ or ~/.config/disper/hooks/ or ~/.disper/hooks/
Directory containing user hooks. These can be enabled with the --plugins option.
/usr/share/disper/hooks/
Directory containing system hooks. User hooks take preference of system hooks or
plugins.
CYCLE
There is a possibility to cycle between different setups with a single disper invocation
using the option --cycle. The options to cycle through are specified by the option
--cycle-stages, which consists of a colon-separated list of disper options. To alternate,
for example, between clone and extend, one could use
disper --cycle-stages='-e : -c' --cycle
Currently the last selected stage is stored in the file
$XDG_CONFIG_HOME/disper/last_cycle_stage (actually the file last_cycle_stage in the
directory of the last configuration file read). This means that when display
configuration is modified by something else than disper (for example by restarting the
computer), cycling will continue from where it was last time, not necessarily from the
current display configuration. This is something that may change in the future.
PLUGINS
It is possible to execute user-supplied hooks on display switch, for example to display a
notification or change the wallpaper. Which ones are enabled is specified by the --plugins
option. System hooks are located in /usr/share/disper/hooks/ while user hooks should be
placed in $XDG_CONFIG_HOME/disper/hooks (or ~/.config/disper/hooks/ or ~/.disper/hooks/).
Each hook is an executable file (which includes scripts). The following environment
variables are available when invoked:
DISPER_VERSION
Version of disper (0.3.1).
DISPER_LOG_LEVEL
Log level: 0 (quiet), 1 (normal) or 2 (verbose).
DISPER_STAGE
Execution stage: prepare or switch. Most plugins will only need to act on the
switch stage, which is just after the display switch has happened. Please make sure
to execute an action only on switch for future compatibility. (There are ideas for
import and export as well.)
DISPER_DISPLAYS
Space-separated list of displays that have output. These names may be slightly
different from what disper uses internally because they have to be valid
environment variable names. (e.g. DFP_0 CRT_0)
DISPER_LAYOUT
One of: clone, top, right, bottom or left.
DISPER_BB_RESOLUTION
Size of full bounding box (e.g. 1024x768).
For each of DISPER_DISPLAYS the resolution of the corresponding display is supplied as
well. If only DFP-0 would be attached, DISPER_DISPLAYS would contain just DFP_0 and the
following variables would be set as well:
DISPER_RESOLUTION_DFP_0
Resolution of display DFP-0 (e.g. 1024x768).
If you want to write your own hook you can also look at the ones supplied with disper in
/usr/share/disper/hooks/.
AUTHOR
Written by Willem van Engen.
SEE ALSO
xrandr(1), nvidia-settings(1)